Allow Turbofan optimization of Ignition generators

src/compiler/bytecode-graph-builder.cc

Index: src/compiler/bytecode-graph-builder.cc
diff --git a/src/compiler/bytecode-graph-builder.cc b/src/compiler/bytecode-graph-builder.cc
index a7b39c209ebb2d1b3fd1094f9cd18131b34b757a..9fc3ede46cb340b2e77eac71776b5e59e8b155b2 100644
--- a/src/compiler/bytecode-graph-builder.cc
+++ b/src/compiler/bytecode-graph-builder.cc
@@ -1367,11 +1367,45 @@ void BytecodeGraphBuilder::VisitForInStep() {
 }
 
 void BytecodeGraphBuilder::VisitSuspendGenerator() {
-  UNIMPLEMENTED();
+  Node* state = environment()->LookupAccumulator();
+  Node* generator = environment()->LookupRegister(
+      bytecode_iterator().GetRegisterOperand(0));
+
+  for (int i = 0; i < environment()->register_count(); ++i) {
+    NewNode(javascript()->CallRuntime(Runtime::kGeneratorWriteRegister),

[Benedikt Meurer, 2016/05/10 10:32:08]

Nit: use StoreRegister or SetRegister instead of WriteRegister

[neis, 2016/05/10 11:32:06]

Done.

+        generator, jsgraph()->Constant(i),
+        environment()->LookupRegister(interpreter::Register(i)));

[Michael Starzinger, 2016/05/10 10:53:05]

nit: Better pull out the
"environment()->LookupRegister(interpreter::Register(i)" into a local variable.
The NewNode function can mutate the current environment and this pattern looks
dangerous. In this case evaluation order should be fine, but I'd prefer to
explicitly sequence it.

[neis, 2016/05/10 11:32:06]

Done.

+  }
+
+  NewNode(javascript()->CallRuntime(Runtime::kGeneratorSetContext), generator);
+  NewNode(javascript()->CallRuntime(Runtime::kGeneratorSetContinuation),
+      generator, state);
 }
 
 void BytecodeGraphBuilder::VisitResumeGenerator() {
-  UNIMPLEMENTED();
+  FrameStateBeforeAndAfter states(this);
+
+  Node* generator = environment()->LookupRegister(
+      bytecode_iterator().GetRegisterOperand(0));
+  Node* state = NewNode(javascript()->CallRuntime(
+      Runtime::kGeneratorGetContinuation), generator);
+
+  // Bijection between registers and array indices must match that used in
+  // InterpreterAssembler::ExportRegisterFile.
+  for (int i = 0; i < environment()->register_count(); ++i) {
+    Node* value = NewNode(
+        javascript()->CallRuntime(Runtime::kGeneratorReadRegister),

[Benedikt Meurer, 2016/05/10 10:32:08]

Nit: use LoadRegister instead of ReadRegister

[neis, 2016/05/10 11:32:06]

Done.

+        generator, jsgraph()->Constant(i));
+    environment()->BindRegister(interpreter::Register(i), value);
+
+    NewNode(javascript()->CallRuntime(Runtime::kGeneratorWriteRegister),
+        generator, jsgraph()->Constant(i), jsgraph()->StaleRegisterConstant());
+  }
+
+  NewNode(javascript()->CallRuntime(Runtime::kGeneratorSetContinuation),
+      generator, jsgraph()->Constant(JSGeneratorObject::kGeneratorExecuting));
+
+  environment()->BindAccumulator(state, &states);
 }
 
 void BytecodeGraphBuilder::VisitWide() {
@@ -1385,8 +1419,8 @@ void BytecodeGraphBuilder::VisitExtraWide() {
 }
 
 void BytecodeGraphBuilder::VisitIllegal() {
-  // Never present in valid bytecode.
-  UNREACHABLE();
+  NewNode(javascript()->CallRuntime(Runtime::kAbort),
+      jsgraph()->Constant(kIllegalBytecode));
 }
 
 void BytecodeGraphBuilder::SwitchToMergeEnvironment(int current_offset) {